<atomic>: atomic_ref<int8_t>::operator--(int) fails to compile #1302
Description
There is an incorrect cast on line 1368 of <atomic>. The cast to _Ty should be _TVal.
_TVal operator--(int) noexcept {
return static_cast<_Ty>(_InterlockedExchangeAdd8(_Atomic_address_as<char>(this->_Storage), -1));
}
Command-line test case
C:\Temp>type repro.cpp
#include <atomic>
int main() {
int8_t x = 0;
std::atomic_ref(x)--;
}
C:\Temp>cl /c /std:c++latest .\repro.cpp
Microsoft (R) C/C++ Optimizing Compiler Version 19.28.29304.1 for x86
Copyright (C) Microsoft Corporation. All rights reserved.
/std:c++latest is provided as a preview of language features from the latest C++
working draft, and we're eager to hear about bugs and suggestions for improvements.
However, note that these features are provided as-is without support, and subject
to changes or removal as the working draft evolves. See
https://go.microsoft.com/fwlink/?linkid=2045807 for details.
repro.cpp
C:\Program Files (x86)\Microsoft Visual Studio\2019\Preview\VC\Tools\MSVC\14.28.29304\include\atomic(1368): error C2440: 'static_cast': cannot convert from 'char' to '_Ty'
with
[
_Ty=int8_t &
]
C:\Program Files (x86)\Microsoft Visual Studio\2019\Preview\VC\Tools\MSVC\14.28.29304\include\atomic(1368): note: static_cast and safe_cast to reference can only be used for valid initializations or for lvalue casts between related classes
C:\Program Files (x86)\Microsoft Visual Studio\2019\Preview\VC\Tools\MSVC\14.28.29304\include\atomic(1367): note: while compiling class template member function 'signed char std::_Atomic_integral<_Ty &,1>::operator --(int) noexcept'
with
[
_Ty=int8_t
]
repro.cpp(5): note: see reference to function template instantiation 'signed char std::_Atomic_integral<_Ty &,1>::operator --(int) noexcept' being compiled
with
[
_Ty=int8_t
]
C:\Program Files (x86)\Microsoft Visual Studio\2019\Preview\VC\Tools\MSVC\14.28.29304\include\atomic(1781): note: see reference to class template instantiation 'std::_Atomic_integral<_Ty &,1>' being compiled
with
[
_Ty=int8_t
]
C:\Program Files (x86)\Microsoft Visual Studio\2019\Preview\VC\Tools\MSVC\14.28.29304\include\atomic(2328): note: see reference to class template instantiation 'std::_Atomic_integral_facade<_Ty &>' being compiled
with
[
_Ty=int8_t
]
repro.cpp(5): note: see reference to class template instantiation 'std::atomic_ref<int8_t>' being compiled
Expected behavior
Should compile successfully.
STL version
Latest